GelMA/tannic acid hydrogel decorated polypropylene mesh facilitating regeneration of abdominal wall defects.

Polypropylene (PP) mesh is a widely used prosthetic material in hernia repair due to its excellent mechanical properties and appropriate biocompatibility. However, its application is limited due to severe adhesion between the mesh and the abdominal viscera, leading to complications such as chronic pain, intestinal obstruction, and hernia recurrence. Currently, building anti-adhesive PP mesh remains a formidable challenge. In this work, a novel anti-adhesive PP mesh (PPM/GelMA/TA) was designed with a simple and efficient in situ gel of GelMA solution on the surface of PP mesh and further crosslinking of tannic acid (TA). It was demonstrated that PPM/GelMA/TA has good biocompatibility and excellent antioxidant property and effectively activates the polarization of macrophages toward the M2 phenotype in vitro. In addition, PPM/GelMA/TA could inhibit the growth of bacteria, which is of great significance for preventing postoperative infections. Furthermore, in the repair of full-thickness abdominal wall defects in rats, PPM/GelMA/TA reduced inflammation, promoted macrophage M2 polarization, and collagen deposition and angiogenesis so that does not cause any abdominal adhesion compared with PP mesh. As a result, our PPM/GelMA/TA shows an attractive prospect in the treatment of abdominal wall defect without adhesions.